how to omit the first GtkTreeSeletion's changed signal

[huzheng <huzheng_001 163 com>]

If I click on a row in a GtkTreeView which has nothing selected a
"changed" signal is emitted by the GtkTreeSelection for the first row
and then subsequently for the row which is selected.

i need to omit the first row 's changed signal.

if a use a omit_first_signal variable which initialize to true,it
work,but when the click row is just the first row,this signal is also
being omit.

then i try to connect to "button_press_event",use
gtk_tree_view_get_path_at_pos to get the click row,but it can't tell
whether it is click on the triangle which use to toggle the row.

anybody solve this problem?

i really think it is gtk's bug.
http://bugzilla.gnome.org/show_bug.cgi?id=94837

i have another question,can i freeze GtkTreeview when inserting a lot
rows? i didn't find any function to do it.